Conformal particle coatings on fibrous materials

Abstract

Methods are provided for uniform deposition of particles on curved surfaces such as fibers and coatings formed by the particles. Particles in the size range of 10-2000 nm are deposited onto a fibrous material via electrostatic interaction between charge modified fiber material surfaces and oppositely charged particles or metal ions. Various nonmetallic, bimetallic or other charged particles are deposited onto a fibrous material via electrostatic interaction between charged modified fibrous material surfaces and oppositely charged particles. Particles can be directly assembled onto a surface of a fibrous material by controlling hydrogen bonding interactions between interfaces of fibers and functionalized particles. Metal particles can also be deposited by in situ synthesis. A method is also provided for layer-by-layer deposition of particles over a fibrous material.

What is claimed is: 
     
       1. A conformal coating for deposition on a non-planar surface of a substrate comprising a plurality of chemically functional particles, wherein:
 the particles have a cross-sectional diameter of 2-2000 nm, 
 the average distance between adjacent particles across the entire non-planar surface is no greater than 10 times the largest cross-sectional dimension of any particle in the plurality, and 
 the attachment of the particles to the surface is through electrostatic self-assembly or covalent bonding. 
 
     
     
       2. The coating of  claim 1  wherein the substrate is a polymer. 
     
     
       3. The coating of  claim 1  wherein the substrate comprises a plurality of fibers. 
     
     
       4. The coating of  claim 3  wherein the fibers have cross-sectional diameters of 10-100 μm. 
     
     
       5. The coating of  claim 3  wherein the fibers are organic or inorganic. 
     
     
       6. The coating of  claim 5  wherein the inorganic fibers comprise glass or ceramic. 
     
     
       7. The coating of  claim 3  wherein the fibers are a bi-component or tri-component fibers. 
     
     
       8. The coating of  claim 1  wherein the substrate is a textile. 
     
     
       9. The coating of  claim 1  wherein the substrate comprises natural or synthetic carbohydrate-based fibers. 
     
     
       10. The coating of  claim 1  wherein the substrate comprises natural protein-based fibers. 
     
     
       11. The coating of  claim 1  wherein the substrate comprises organic synthetic fibers capable of participating in hydrogen bonding. 
     
     
       12. The coating of  claim 1  wherein the particles are metallic. 
     
     
       13. The coating of  claim 12  wherein the particles comprise metal or metal oxide. 
     
     
       14. The coating of  claim 1  wherein the particles are organic. 
     
     
       15. The coating of  claim 1  wherein the particles are inorganic and non-metallic. 
     
     
       16. The coating of  claim 1  wherein the particles comprise SiO 2 . 
     
     
       17. The coating of  claim 1  wherein the particles are hybrid particles. 
     
     
       18. The coating of  claim 1  wherein the particles are spherical and/or non-spherical. 
     
     
       19. The coating of  claim 1  wherein the particles are functionalized. 
     
     
       20. A polymeric non-planar surface comprising the conformal coating of  claim 1 .